What does "we wrap the individual and reuse the codons" mean in the paper "Grammatical Evolution" by Neill and Ryan?
In GE, the genotype is a linear sequence of codons. By &quot;wrapping&quot; it, you make it a circular sequence that never ends. It allows you to build a bigger tree, while having only a few codons. Still, it is possible to find such a combination of a genotype and a grammar that defines an infinitely deep expansion — such combinations are hardly suited for practical purposes.
I learned about GE recently. I implemented a GP/GE system to solve the Santa Fe Trail problem. I chose not to perform wrapping to make genotype-to-phenotype mapping more predictable (I always generate enough codons to complete a grammar expansion, and prune unused tails). I also went with a subtree crossover, and a subtree-local mutation, which effectively make the system more a classical GP (with a fancy genotype-to-phenotype mapping) than GE. So there are some options.